Peristenus braunae, Goulet & Mason, 2006

Goulet, Henri & Mason, Peter G., 2006, Review of the Nearctic species of Leiophron and Peristenus (Hymenoptera Braconidae: Euphorinae) parasitizing Lygus (Hemiptera: Miridae: Mirini:), Zootaxa 1323 (1), pp. 1-118 : 41-43

Peristenus braunae n. sp.

( Fig. 15 , Table 9)

Type material. Type locality: Canada, Alberta, north of Twin Lakes. Holotype , female ( CNCI), labelled: [ White ] “ Canada: AB, N of Twin Lakes, 27.VI. 2003, 639m 57 o 30.823'N 117 o 28.825'W Goulet, Carcamo & Otani”; [Red] “ HOLOTYPE Peristenus braunae CNC No. 23474 ” Condition of holotype : excellent. Allotype, male, with same data as holotype. Except for specimens from low elevation in coastal British Columbia, the remaining specimens, mentioned under “Material examined and range”, are paratypes .

Origin of species name. This species is named in honour of Lorraine Braun who reared this species from Lygus and helped to clarify a difficult part of the P. pallipes complex.

Diagnosis. Clypeus black, punctures dense on head (between lateral ocellus and inner eye margin) and less dense on frons (surface smoother with shiny spaces between punctures), occurring in boreal region mainly after mid June.

Description. FEMALE. Colour. Head and mesosoma black, clypeus usually black, metasoma usually black, rarely brown. Legs straw coloured or light reddish brown (metacoxa commonly brown or black (as in Fig. 5 ), uncommonly straw coloured). Metatibia light reddish brown and apical half often gradually becoming reddish brown, thus concolorous or almost so (as in Fig. 11 ). Metatarsomeres 1–5 as dark as apex of metatibia; palpi, tegula and mandible (except apex), straw coloured. Scape to flagellomere 2 straw coloured, then after flagellomere 3–4 brown to dark brown. Stigma uniformly dark brown or with a paler spot in basal half.

Structure. Flagellum with 19–22 flagellomeres (respectively 14%, 51%, 31% and 4% of 106 specimens) and flagellomeres enlarged in apical 0.5 with at most 2 preapical flagellomeres quadrate or subquadrate. Genal length behind eye 1.00–1.31 times as long as length of eye. Height of eye 1.06–1.17 times as long as minimum distance between inner eye margins (as in Fig. 17 ). Maximum width of head behind eyes subequal (0.95–0.99) to maximum head width at eye level. Occipital carina developed in dorsal third (as in Fig. 33 ). Metasomal tergum 1 with lateral edges clearly convergent (posterior margin 1.8–2.4 times as wide as narrowest width near base) and elongate (medial length of tergum 1.63–2.00 times as long as maximum width at posterior end) (as in Fig. 68 ). Radial cell length 0.83–1.00 as long as stigma width (as in Figs. 58–63 ). Forewing with vein r usually developed and short (as in Figs. 61, 62 ) and basal cell (except extreme base) pubescent (as in Fig. 54 ).

Sculpture. Punctures on vertex 5–10 µm in diameter, and on frons and mesoscutum about 10–15 µm in diameter (a little larger than diameter of ommatidia). Punctures 20–25 µm apart on vertex and 5–15 µm apart on frons (thus, in most specimens with shiny surface between punctures) and between lateral ocellus and inner eye margin (as in Fig. 26 ), 5–10 µm apart near antennal socket, 20–25 µm apart on mesoscutum. Punctures in front of median ocellus in most specimens coarsely and densely punctate. Punctures on mesopleuron dense and in most specimens coarsely punctate on anteroventral surface of mesepisternum in lateral view. Clypeus generally impunctate or mostly so over surface, or occasionally densely punctate. Metasomal tergum 1 with about 10–12 longitudinal ridges, these often anastomosing on disc and forming a puncture­like sculpture.

MALE. Colour. Generally as in female, but metacoxa usually brown, sometimes brown on outer surface and paler on inner and ventral or, rarely completely straw coloured.

Structure. Flagellum with 21–24 flagellomeres (respectively 29%, 54%, 14% and 3% of 56 specimens) and flagellomeres narrow in apical half. Height of eye 0.91–1.00 times as long as minimum distance between inner eye margins. Otherwise structure and sculpture as in female.

Geographical variation. There are a few differences between specimens from western and eastern Canada. In the West , the mesocoxae are often reddish brown to black and the clypeus is almost always smooth or a little punctate. In the East , the mesocoxae are straw coloured to light reddish brown and the clypeus is normally punctate. In specimens from coastal British Columbia, the flagellomere frequency distribution is higher, with most specimens from coastal regions having 21 flagellomeres in females, 22 or 23 in males. The coastal British Columbia sample is small (19 female and 12 male flagella counted) so it is unclear if the population is a geographical variant of P. braunae or another cryptic species. Because of this character variation, specimens from coastal regions of the Pacific were excluded from the paratype series .

Taxonomic notes. Among the species of the P. pallipes complex associated with Lygus , P. braunae is nearest P. dayi . Adults of the two species differ on flagellomere frequency, mesocoxa and metacoxa colour in females, clypeus and mesepisternum puncture development, and flight period.

The nearest populations of P. braunae to those of P. dayi are 300 km apart. The populations of P. braunae nearest to those of P. dayi are not more similar than distant populations of both species. There is probably no gene flow. Thus, the boreal population of P. braunae is specifically distinct from the eastern temperate P. dayi . A summary of measurement differences between P. braunae and P. dayi is given in Table 9.

Host and biological notes. Adults of this species have been reared mainly from Adelphocoris lineolatus and rarely from Lygus lineolaris . Adults occur from early June to mid August with a peak of abundance from late June to early July. This is a univoltine species on nymphs of the first generation of Lygus .

Material examined and range. 167 (62♂, 105♀) adults were studied. Of these, 7 were reared from Miridae and 156 were field collected. The species is known from boreal regions of North America between the Northwest Territories and Alaska to southwestern British Columbia, south to montane regions of California and Utah and coastal regions of New Brunswick and Nova Scotia.

CANADA. NT: Aklavik (1♀) ; Norman Wells (1♀); Wrigley (1♀); NS: Cape Breton Highlands Nat. Park , Meat Cove (1♀) ; Sable Island (1♂) ; Yarmouth (1♂, 1♀). NB: Kouchibouguac Nat. Park (5♂, 3♀) . QC: vic. Frelighsburg , 45º05'N 72º50'W (1♂) ; vic. La Corne , 48º24'19''N 78º00'12''W (1♂, 13♀) ; La Vérendrye Prov. Park, 47º36'57''N 77º33' 42''W (15♂, 8♀) ; Matagami , 49º45'08''N 77º37'14''W (5♂, 5♀) . MB: Brandon (1♀). SK: E lbow (2♀); vic. Saskatoon , 52º09.1'N 106º34.9'W (1♂) . AB: Banff (1♂); Beaverlodge, Mountain Trail (2♂, 3♀) ; Blairmore (1♀); Burmis (1♂, 1♀); Dunvagan (1♂, 1♀); Gilchrist Beach, Aden (1♀); N of Grande Cache , between 54º09'N 118º45'W and 54º34'N 118º42'W (1♂, 3♀) ; 1 km E Jasper Nat. Park , 53º14.138'N 117º49.418'W (1♂) ; vic. La Crete , 58º01.257'N 116º19.621'W (1♂) ; Lethbridge (3♂, 18♀); Lethbridge , 49º42.279'N 112º44.951'W (1♀) ; Long view, 50º24.335'N 114º31.028'W (2♀) ; Milk River , 49º08'N 110º48'W (1♀) ; Oyen (1♀); Saskatoon Mtn. , 55º13.204'N 119º17.042'W (3♂, 4♀) ; Shaunessey (1♂); Tompcam’s Landing , 57º59.034'N 117º06.291'W (1♀) ; vic. Twin Lake , 57º30.823'N 117º28.825'W (2♂, 4♀) ; Waterton Lakes Nat. Park, Cameron Lake (1♀) ; Waterton Lakes Nat. Park , 1300 m (4♀) . BC: 15 km N Boston Bar , 49º58'39''N 121º29'49''W (4♂, 4♀) ; 20–25 km E Chilliwack Lake Rd. (1♀) ; Cowichan Lk. (1♀); Crownest (1♂, 1♀); Diamond Head trail near Squamish (1♀); Fort St. John (1♂) ; Harrison Bay (1♀) ; vic. Langley (4♀); vic. Lytton , 50º31'20''N 121º43'57''W (1♀) ; vic. Lytton , 50º14'38''N 121º34'35''W (1♀) ; Madden Lake , Oliver (2♀) ; Saltspring Is. Tuam Mtn. (1♂); Summit Lake , mi 392 Alaska Hwy. (1♀) . USA. AK: Fairbanks (1♀) . CA: Nevada Co., Sagehen Cr., 13 km W Truckee (1♂) . CO: Doolittle Ranch (1♂, 2♀); Estes Park (3♂); 3 km S Meeker (2♂, 2♀) . UT: Summit Co., Cobble Cr. (1♀) .

Figures

FIGURES 13–24. 13–22. Frontal view of head. Code: “a” ventral edge of clypeus. 23–24. Dorsal view of head.

FIGURES 1–5. Habitus with frontal view of head. Codes: “a” clypeal colour; “b” metatibial colour; “c” metacoxal colour; “d” forewing colour; “e” mesoscutal colour.

FIGURES 6–12. 6–9. Habitus with frontal view of head. Codes: “a” clypeal colour; “c” metacoxal colour; “f” metafemoral colour; “g” facial colour; “h” genal spot. 10–12. Lateral view of metatibia.

FIGURES 25–36. 25–27. Dorsal view of head with insert to show sculpture. 28–31. Lateral view of head. 32–33. Posteroir view of head. Code: “a” dorsal end of occipital carina. 34. lateral view of antenna. 35–36. Last five flagellomeres in lateral view.

FIGURES 67–78. 67–68. Dorsal view of metasomal tergum 1. 69–70. Ventral view of metasomal segment 1. 71–72. Lateral view of seven last flagellomeres. 73–74. Lateral view of first three flagellomeres. 75–76. Dorsal view of protarsus. 77–78. Lateral view of metasoma.

FIGURES 50–58. 50–52. Forewing. 53–54. Basal and subbasal cells of forewing. 55–58. Radial cell and stigma of forewing.

FIGURES 59–66. 59–63. Radial cell and stigma of forewing. 64. Hind wing. 65–66. Basal and subbasal cells of hind wing.